1. Field of Invention
The invention relates to a non-imaging optical lens and a light-emitting module having the lens which achieves effects of uniform light.
2. Related Prior Art
A general optical lens, which is particularly applicable for a light emitting diode, is used as a secondary optical lens for converging or diverging the light beam. However, it might incur facula.
As disclosed in Taiwan Publication Patent No. M411533, a LED lens has advantages of diffusion light and uniform light. The aforementioned LED lens has a concave condensing part 11 at the bottom of the lens and a concave diffusing part at the center of the top of the lens, so as to diffusing the light. Besides, the lens further has a circular inclined wide-angle part at a peripheral of the top of the lens. However, it has limited uniform light distribution.
In addition, Taiwan Publication Patent No. 201113555 relates to a non-imaging condensing lens, which comprises a plurality of annular protruding prisms to uniformly concentrate light (such as sunlight) on a solar panel for collection. Nevertheless, the lens is typically applicable for the parallel light beam.